Comet visibility depends on its survival passing around sun

A graphic showing Comet ISON’s projected path through the sky. The comet is expected to be brightest Dec. 1. (Image provided by Ken Stage/ St. George Observatory)

Morgan City, La.

By ZACHARY FITZGERALD
zfitzgerald@daily-review.com

St. Mary Parish residents may be able to see Comet ISON Sunday morning, which has taken a 25,000-year journey to pass by Earth and will never return after this visit, assuming the comet does not burn up when it passes the sun on Thanksgiving Day, said Ken Stage of St. George Observatory in Schriever.
Comet ISON must survive perihelion, which is the closest part of its approach to the sun, in order to not disintegrate, he said. The comet is projected to be brightest in the sky looking south, southeast Sunday just above the horizon about 30 minutes before sunrise, Stage said.
The comet was discovered in September 2012 by two astronomers in Russia, according to a CNN.com article.
Venus is the brightest object in the sky after the sun and the moon, Stage said. If the comet increases in brightness similar to Venus, then even people living in large cities can look up and see the comet, Stage said. “If it gets to a negative 5.5 magnitude, it’ll be visible in the daytime sky.”
All of St. Mary Parish will be able to view the comet if the area is dark enough, Stage said. “The plus side of this whole thing is that we’re going to go through the new moon in early December so the moon will not be a contributing factor,” Stage said.
“We’re long overdue for a good comet in the northern hemisphere. It seems in the past six or seven years it’s been everyone else in the southern hemisphere that you had big comets,” Stage said.
The comet is classified as a sun-grazing comet because it is going to pass so close to the sun, Stage said. The designation of the comet is C/2012 S 1. “The ‘C’ stands for simply we’ll never see it again. Once it leaves us, it’s headed out towards the Oort Cloud region of space from whence it came. It started its journey approximately 25,000 years ago to give a wonderful Christmas gift to the people of St. Mary Parish,” Stage said. The comet should be visible to the naked eye Sunday if the comet does not disintegrate when it passes in front of the sun, he said.
Stage is planning to watch the comet’s encounter with the sun Thanksgiving Day through a telescope at the St. George Observatory.
According to a CBSnews.com article Monday, the comet was expected to reach 828,000 miles per hour by the time it makes its way around the sun.
The comet will get no closer than 40 million miles from Earth with the closest approach expected to be Dec. 26, the article stated.
As of Wednesday morning, an NBCnews.com article cited experts saying the comet stands a 30 to 40 percent chance of surviving its trip by the sun.